Reproduction and Inheritance Flashcards
What are the main features of asexual reproduction?
Asexual reproduction needs only one parent. Since there is only one parent, there is no fusion of gametes and no mixing of genetic information. As a result, the offspring are genetically identical to the parent and to each other. They are clones.
What are the main features of sexual reproduction?
Two different sexes take part in the process.
Testis in male produces the male gametes or sperms and the ovary in female produces female gametes or ova. Sperms and ova come into contact with each other and fuse to form a zygote or egg by a process called fertilisation.
It involves slow multiplication.
How are plants adapted for fertilisation?
Fury stigma, pollen grains
Insect pollination
Large, brightly coloured petals, often sweetly scented, usually contain nectar, moderate quantity of pollen - less wastage than with wind pollination, pollen often sticky or spiky - to stick to insects, anthers firm and inside flower - to brush against insects, stigma inside the flower - so that the insect brushes against it, stigma has sticky coating - pollen sticks to it
Wind pollination
Small petals, often brown or dull green - no need to attract insects, no scent, no nectar, pollen produced in great quantities - because most does not reach another flower, pollen very light and smooth - so it can be blown in the wind and stops it clumping together, anthers loosely attached and dangle out - to release pollen into the wind, stigma hangs outside the flower - to catch the drifting pollen, stigma feathery or net like - to catch the drifting pollen
Conditions needed for germination
Moisture
Oxygen. All green plants need oxygen to “breathe” or respire
Warmth
Female reproductive system
Ovaries- produce eggs
Oviducts- carry the eggs to the uterus, is the site of fertilisation
Uterus- develops the fertilised egg on the placenta
Cervix- entrance to uterus
Male reproductive system
Testis- produce sperm cells, they are stored in the epididymus
The prostate- adds fluid to the sperm, creating semen (as does the seminal vesicles)
The urethra carries sperm to the end of, and out of the penis.
Theroleoftheplacentainthenutritionof
the developingembryo
The embryo can’t breath, digest or excrete.
Blood vessels inside the placenta can absorb the digested food molecules and oxygen that the embryo needs to survive. Waste products will be taken out of the embryo and put back into the mothers blood stream for her to excrete.
Howis thedevelopingembryoprotectedby
amniotic fluid
The fluid (mainly water) cannot be compressed- it absorbs pressure- so any force on the uterus wall will not harm the embryo.
Fertilisation
Is the fusion of the male and female gametes
Pollination
The process in which pollen from one flower is transferred to another flower, before fertilisation can take place.
Vaccinations
When a small dead part of the pathogen is injected into the body to enable the white blood cells to make memory cells in order to be able to make the right antibodies
What is amniotic fluid?
The fluid surrounding developing fetus in the uterus, which protects the foetus from mechanical damage.
What is the anther?
The male part of a flower that produces pollen
What is asexual reproduction?
The production of new individuals without fertilisation, from division of body cells in the parent.
What is the carpel?
The female structure in flowers which contains one or more ovaries and their stigmas and styles.
What is a cutting?
A part taken from a plant and treated so that it grows into a new plant, a form of artificial asexual reproduction of plants.
What is an embryo?
A developing young organism, where cell division and differentiation are taking place rapidly. In plants it develops in the seed. In humans, the embryo is the stage between zygote and fetus.
What is a fetus?
The name given to the developing baby in the uterus
What is fruit?
The soft, fleshy structure surrounding a seed, formed from the ovary after fertilisation.
What is a gamete?
A sex cell
What is the ovary?
A structure that contains immature egg cells
