Fill in the blanks
Question 1
The force with which sap is pulled up by plants is called ............... .
Answer
The force with which sap is pulled up by plants is called transpiration pull.
Question 2
Blood group AB has ............... and antibodies ............... .
Answer
Blood group AB has both antigens and antibodies are absent.
Question 3
A mass of unorganized cells growing in a nutrient medium is called ............... .
Answer
A mass of unorganized cells growing in a nutrient medium is called callus.
Question 4
A ............... is formed as a result of fertilization.
Answer
A zygote is formed as a result of fertilization.
Question 5
Fertilization takes place in the fallopian tubes or ............... .
Answer
Fertilization takes place in the fallopian tubes or oviduct.
Question 6
Living organisms that cannot make their own food but consume either plants or other animals, are called consumers or ............... .
Answer
Living organisms that cannot make their own food but consume either plants or other animals, are called consumers or heterotrophs .
Question 7
............... are also called nature's scavengers.
Answer
Decomposers are also called nature's scavengers.
Write true or false. Correct the false statements
Question 1
Xylem is the food-conducting tissue in plants.
Answer
False
Correct statement — Phloem is the food conducting tissue in plants.
Question 2
Blood group O is a universal donor while AB is a universal recipient.
Answer
True
Question 3
Lymph nodes produce erythrocytes.
Answer
False
Correct statement — Lymph nodes produce Lymphocytes.
Question 4
Ovulation generally occurs on the 14th day of the menstrual cycle.
Answer
True
Question 5
Non-living things in the environment are called its biotic components.
Answer
False
Correct statement — Non-living things in the environment are called its abiotic components.
Question 6
Animals that eat other living animals are called carnivores or secondary consumers.
Answer
True
Question 7
Green plants that fix the solar energy constitute second trophic level.
Answer
False
Correct statement — Green plants that fix the solar energy constitute first trophic level.
Differentiate between
Question 1
Osmosis and diffusion
Answer
| Sl. No. | Osmosis | Diffusion |
|---|---|---|
| 1. | The movement of water molecules through a semi-permeable membrane from an area of its higher concentration to an area of its lower concentration is called Osmosis. | The movement of salt or mineral molecules from a region of their higher concentration to a region of their lower concentration is called Diffusion. |
| 2. | It takes place only in a liquid medium. | It takes place in any medium such as solid, liquid and gas. |
| 3. | It requires a semi-permeable membrane. | It does not require any semi-permeable membrane. |
| 4. | It is a slow process. | It is comparatively a faster process in gases, slow in liquids. |
Question 2
Diffusion and active transport
Answer
| Sl. No. | Diffusion | Active transport |
|---|---|---|
| 1. | It is the movement of molecules or ions of a substance from a region of their higher concentration to a region of their lower concentration. | It is the movement of ions of a substance from their lower concentration region to their higher concentration region using energy. |
| 2. | It is the movement of solute or solvent molecules. | It is the movement of ions only (no water). |
| 3. | No cell energy is needed. | Cell energy is needed in the form of ATP. |
| 4. | It occurs through a non-living permeable membrane. | It occurs through a living selectively permeable membrane. |
Question 3
Auricles and Ventricles
Answer
| Sl. No. | Auricles | Ventricles |
|---|---|---|
| 1. | Upper two chambers of heart are called Auricles. | Lower chambers of heart are called ventricles. |
| 2. | They have thinner walls than ventricles. | They have thick walls. |
| 3. | They receive blood from different part of the body. | They pump blood out of heart. |
Question 4
Cutting and Grafting
Answer
| Sl. No. | Cutting | Grafting |
|---|---|---|
| 1. | In this method, a part of stem with an axillary bud is cut and planted in moist soil. | In this method, a stem cutting (scion) from one plant is attached and tied to the rooted stem (stock) of another plant. |
| 2. | New plant is identical to parent plant. | The plant is superior than both the parent plants. |
| 3. | Cutting is used in propagation of Rose, Cacti, Bougainvillea etc. | Grafting is used in Rose, Mango, Guava etc. |
Question 5
Ovaries and Testes
Answer
| Sl. No. | Ovary | Testes |
|---|---|---|
| 1. | Ovaries are part of the female reproductive system. | Testes are part of the male reproductive system. |
| 2. | The ovaries are situated in the pelvic or hip region. | Testes are located outside the abdomen in a sac-like structure called scrotum. |
| 3. | Eggs (ova) are produced and released by ovaries. | Sperms are produced in testes. |
Question 6
Food chain and Food web
Answer
| Sl. No. | Food chain | Food web |
|---|---|---|
| 1. | A series of organisms that are linked to each other through a process of eating and being eaten form a food chain. | Several food chains are interconnected to form a food web. |
| 2. | It is basic chain showing flow of energy. | It is a complex network showing flow of energy at different trophic levels in different food chains. |
Give reasons for the following
Question 1
Mineral solutes do not pass on from the roots into the soil but water is drawn into the roots from the soil.
Answer
Mineral molecules are more concentrated inside the root hair cells than in the soil outside. Still, mineral solutes do not pass on from the roots into the soil but water is drawn into the roots from the soil. It is because plants use the process of active transport and absorb against the gradient at expense of energy. The movement of minerals ions from a region of their lower concentration to a region of their higher concentration is called active transport. This process involves the use of energy (ATP).
Question 2
White blood cells are described as the 'soldiers' of the body.
Answer
White blood cells are described as the 'soldiers' of the body because it destroys the harmful microorganisms and foreign particles and prevents infection from spreading in the body.
Answer the following in detail
Question 1
Discuss the ascent of sap with the help of a neatly labelled diagram.
Answer
Ascent of sap in plants is described below:
- Root hair cells absorb mineral salts mainly by active transport. The mineral salts then reach the root cortex.
- Root hair cells also absorb water from the soil through osmosis.
- As mineral salts get accumulated in the xylem, the water concentration gets reduced in it. This creates a concentration gradient that is strong enough to draw water and minerals to move towards the stem. The pressure developed in the roots due to the continuous inflow of water helps in pushing the plant sap upwards. It is called root pressure.
- Further on, water moves through the xylem up the stem, then to the leaves. This happens due to a pull created by transpiration. It is called transpiration pull.
- Water and minerals absorbed by roots are conducted upwards through xylem to other plant parts. This upward movement of cell sap, which contains water and minerals, is called ascent of sap.
Question 2
Name the four blood groups in human beings. On what basis are they named?
Answer
The four blood groups in human beings are A, B, AB and O. They are named on the presence or absence of specific antigens.
Question 3
Name several types of vegetative propagation in flowering plants with an example of each kind.
Answer
Vegetative reproduction in plants are of two types. They are:
- Vegetative propagation by natural methods
- By underground stem — Potato
- By aerial stem — Strawberry
- By root — Dahlia
- By leaves — Bryophyllum
- Vegetative propagation by artificial methods
- Cutting — Sugarcane
- Layering — Rose
- Grafting — Mango
- Tissue Culture — Orchids
Question 4
Write about the different parts of the female reproductive system of human beings.
Answer
The reproductive system in females consists of a pair of ovaries, the fallopian tubes or oviducts and the uterus. The ovaries are almond-sized oval glands situated in the pelvic or hip region. They produce the eggs or ova. The mature egg moves through funnel-shaped muscular tubes called fallopian tubes or oviducts towards the uterus. The uterus lies in the lower abdomen behind and above the urinary bladder. The uterus is a hollow, muscular pear-shaped organ. It is in the uterus that the zygote develops into a baby. The lower part of the uterus is called cervix. The cervix is narrow and opens to the outside through a muscular tube called the vagina. The vagina receives the sperms. It also serves as the birth canal through which the mature baby is delivered.
Question 5
Explain the flow of energy in a food chain with the help of a diagram.
Answer
Green plants convert solar energy into chemical energy present in food. Some energy gets stored in plants while the rest is used up by them. When the plants are eaten by herbivores, the energy stored in them is transferred to herbivores. Herbivores use some of the energy for their activities and store a part of it in their body. This stored energy is further transferred to carnivores when they eat herbivores. Thus, as one organism eats the other, energy passes on from producers to herbivores and then to carnivores. The given diagram shows the flow of energy in a food chain:
The diagram
Question 1
The diagram illustrates the structure of a flower. Label the parts a to e.
Answer
The parts labelled a to e are:
a → Petal (corolla)
b → Stigma
c → Anther
d → Ovules
e → Thalamus