IGCSE Biology Paper-3: Specimen Questions with Answers 266 - 268 of 358

Passage

Many flowering plants can reproduce sexually and asexually.

Question 266 (6 of 7 Based on Passage)

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Define the term asexual reproduction.

Explanation

Asexual reproduction is a type of reproduction where fertilization does not take place as only a single parent is involved. Offspring produced is identical to the parent because they are produced as clones.

Question 267 (7 of 7 Based on Passage)

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Fig. shows a potato plant, Solanum tuberosum, grown from a tuber. The tubers that potato plants are grown from are commonly referred to as seed potatoes.

Potatoes can reproduce asexually by means of tubers. The parent plant produces underground stems, which eventually form tubers.

With reference to Fig. describe how tubers are formed from the underground stems in potatoes.

Diagram of Plant

Explanation

Tuber

  • Irregularly shaped swollen stem.
  • Stores plenty of food.
  • It is differentiated into nodes and internodes. The ‘eyes’ on potato tuber indicate axillary buds at the nodes.
  • It bears scaly leaves. The leaves do not store food.
  • Axillary buds arise at the nodes.
  • Does not bear roots.
  • E. g. , Solanum tuberosum (potato) .
Tuber of Potato

Passage

shows a diagram of the human female reproductive system.

Reproductive System

Question 268 (1 of 4 Based on Passage)

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Short Answer▾

Using letters P – U, identify the parts of the human female reproductive system in Fig. 11.1.

where eggs are made …

where fertilization occurs …

where implantation of the zygote occurs …

Explanation

where eggs are made … T …

where fertilization occurs … S …

where implantation of the zygote occurs … P …

Ovary

  • The ovary is the primary female sex organ.
  • Ovary produces ova and secretes female sex hormones viz. , estrogens and progesterone

Fertilization

Fusion of a haploid male gamete and a female gamete to form a diploid cell, the zygote, is called fertilization. Fusion of gametes in the fertilization is called as syngamy. Fusion of cytoplasm is plasmogamy and fusion of nucleus is karyogamy.

Implantation

In humans, implantation is the stage of pregnancy at which the embryo adheres to the wall of the uterus. At this stage of prenatal development, the conceptus is called a blastocyst. It is by this adhesion that the embryo receives oxygen and nutrients from the mother to be able to grow.