✓ Board-verified
Science · 2023 · 5 marks
CBSE 2023 · Region 6 · Set 3 · Q35
(a)Name the two types of pollination and differentiate between them.(b)Explain the post fertilization changes that occur in the ovary of a flower.(c)Given below is a diagram of a germinating seed. Label the parts that
(a)
Name the two types of pollination and differentiate between them.
(b)
Explain the post fertilization changes that occur in the ovary of a flower.
(c)
Given below is a diagram of a germinating seed. Label the parts that
Marking-scheme solution
(a) Two types of pollination:
Self pollination
Cross pollination
| Self pollination | Cross pollination |
| Transfer of pollen grains from stamen to the stigma of pistil of the same flower or another flower of the same plant. | Transfer of pollen grain occurs from one flower to another flower of a different plant. |
(b)
Zygote divides several times to form an embryo within the ovule.
The ovule develops a tough coat and is converted into a seed.
The ovary grows rapidly and ripens to form a fruit
Sepals, petals stamens dry and fall off.
(c) A → Plumule
B → Radicle
C → Cotyledon
As a dehydrating agent
(ii)
• The process in which unsaturated hydrocarbons/compounds react with hydrogen in the presence of a catalyst (Ni / Pd) to give saturated hydrocarbon.
Used in the hydrogenation of vegetable oils which are converted into fats with saturated carbon chains.
(c) Sex determination in Human beings
PARENTS:
OR
(c) The \(\displaystyle 23{ }^{\text {rd }}\) pair or the sex chromosome in human females contains 'XX' chromosome. At the time of gamete formation, each gamete gets one X-chromosome.
More from How do Organisms Reproduce?
- (i) Where are testes located in the human males and why? State two function of the testes. (ii) In the human…2023 · asked 3×
- A zygote is formed by the fusion of a male gamete and a female gamete. The number of chromosomes in the…2024 · asked 3×
- When a human egg is fertilized by a sperm having 'Y' chromosome, the zygote has the following combination of…2026 · asked 3×
- Pollination is an important process in sexual reproduction of plants. It is an essential process that…2024 · asked 3×
- Attempt either or: Observe the given diagram and answer the questions that follow: (i) Give the name of the…2026 · asked 3×
- Plants which bear unisexual flowers are:2023 · asked 3×
- Given below are certain situations. Analyse each and describe its possible impact: (i) A population of…2026 · asked 3×
- Spirogyra, despite being a multi-cellular organism, still shows a simple reproductive method. Select the…2026 · asked 3×
CBSE Class 10 Science past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.