Flashcards in CH-16 REPRODUCTION IN PLANTS Deck (38)
What are chromosomes and what do they contain?
Chromosomes are the long thread of DNA found in the nucleus of a cell, and they contain sets of instructions known as genes.
What is a gene?
a length of DNA that is the unit of heredity and codes for specific.
Explain why offspring produced asexual reproduction are genetically identical to each other.
Genes are the same.
What is fertilisation?
the fusion of gamete nuclei
What is sexual reproduction?
a process involving the fusion of the nuclei of two gametes to form a zygote and the production of the offspring that are genetically different from each other.
What is asexual reproduction?
a process resulting in the production of genetically identical offspring from one parent
What is the diploid cell?
having two sets of chromosomes
What is the haploid cell?
having one set of chromosomes
What is meiosis?
reduction division in which the chromosome number is halved from diploid to haploid
what is mitosis?
nuclear division giving rise to genetically identical cells in which the chromosome number is maintained by the exact duplication of chromosomes.
What is a gamete?
a haploid cell that fuses with another haploid gamete to produce a zygote
What is a zygote?
a diploid cell formed by the fusion of the nuclei of two gametes
Why do gametes contain only half the normal number of chromosomes?
so that when their nuclei fuse at fertilisation, the new cell formed will have the normal two sets of chromosomes.
Name one part of your body where you have diploid cells.
any part of the body
Give one example of a haploid cell.
egg or sperm
When do cells divide by meiosis?
during the formation of gametes
What is pollination?
the transfer of pollen grains from the male part of the plant (anther of stamen) to the female part of the plant (stigma)
What is sepal?
protects unopened flower
What are petals?
brightly colored in insect-pollinated flowers to attract insects.
What is anther?
it produces and releases the male sex cells- pollen grain
What is stigma?
top of the female part of the flower which collects pollen grains.
What is ovary?
produces the female sex cell - ovum
What is ovule?
contains the female sex cells - found inside the ovary
Features of insect pollinated flower.
1. large and bright colored to attract insects
2. scent and nectar are present
3. moderate no or pollen grains
4. anther inside flower
5. stigma present inside flower
features of wind pollinated flower.
1. small and dull petals
2. scent and nectar absent
number of pollen grains- large amount
3. smooth, small and light pollen grains
4. anther outside the flower
5. stigma outside the flower.
What is self pollination?
the transfer of pollen grains from the anther of a flower to the stigma of the same flower, or a different flower on the same plant.
What is cross- pollination?
the transfer of pollen grains from the anther of a flower of the stigma of a flower on a a different plant of the same species.
What is the function of flower?
In which part of a flower are male gametes made?