Module 1 : Heredity Flashcards
What is the bulb vegetative reproduction, give an example ?
underground storage organ that consists of a short stem surrounded by fleshy leaves - lateral buds eg Onions
What is runners vegetative reproduction give an example ?
side branches that grow close to the ground and develop new plantlets on them eg strawberries
How do animals reproduce ?
Both asexual and sexual. Asexual like budding (coral) or regeneration (flatworms). Sexual can be seen in external or internal fertilisation
What are two advantages and disadvantages of Sexual reproduction
A : high genetic diversity + facilitates adaptation + less prone to environmental changes
D : Energy costly + requires two parents
Name two advantages and disadvantages of Asexual reproduction
A : energy efficient + requires 1 parent + no courtship required
D : less genetic diversity + more prone to environmental changes
List advantages and disadvantages of Internal and external fertilisation ?
A I : fertilisation more likely to occur + offspring more likely to survive
D I : higher amount of energy to occur + less offspring produced
A E : Little energy required + large amount of offspring produced
D E : many gametes go unfertilised + offspring not protected by parents
Explain how fungi reproduce asexually ?
By the 1 of the processes known as spores. Fungi produce spores that disperse from the parent organism by either floating on the wind or hitching a ride on an animal
Explain how fungi reproduce sexually ?
Specialised Haploid Hyphae fuse together to form a diploid cell (2n) —- This genetically unique diploid cell then undergoes meiosis to produce new haploid (n) spores.
Explain binary fission ?
- cell elongates - builds more cell wall
- bacteria genome replicates and remains attached to the membrane.
- Duplicated DNA beings to replicate, moving towards the poles as the cell elongates more
- cleavage furrows begins to form and cell wall forms in cleavage furrows
- two identical are now produced.
Explain budding ?
form of asexual reproduction in which the new organism arises as an outgrowth or bud from the parent
commonly seen in fungi and protists
List the male reproductive parts of a flower and describe the function of each part.
The male gametophyte is the pollen grain, held on the anther at the top of stamen. It is used for to be picked up by bees or wind and transferred onto the female pistil to undergo fertilisation.
label the female reproductive parts of a flower and describe the function of each part.
The pistil includes the stigma, style and ovary. The stigma is used for the pollen grains to germinate, the pollen grains go down the style to reach the ovary in which the egg is held.
Distinguish between pollination and fertilisation in plant reproduction.
Pollination refers to when pollen from the anther is transferred on the female pistil of a angiosperm. Fertilisation however refers to the fuse of haploid gametes to fertilise into a diploid zygote.
Identify two ways in which the reproductive structures differ between wind-pollinated and insect-pollinated plants.
- Wind pollinated plants need to have pollen grains much lighter in weight due to the necessity of being carried by wind.
- Insect pollinate plants need to have more sticky pollen grains in stick onto insects such a bee’s and then carried to another plant.
Describe two pollination mechanisms in plants and explain how they ensure the continuity of the species
- Cross pollination occurs when pollen is delivered from the stamen of one flower to the stigma of a flower on another plant of the same species. This mechanism ensures greater variation in the offspring. Plants additionally use self-pollination is the transfer of pollen from the anther is deposited on the stigma of the same flower.
Identify Mitosis and meiosis
Mitosis - process where a single cell divides into TWO identical daughter cells
Meiosis - process where a single cell divides twice to produce FOUR cells containing half the original amount of genetic information
What are the five hormones
- **FSH :** **Follicle Stimulating Hormone →** from follicles – increases oestrogen and stimulates follicle growth - causes egg to mature and ovaries to secrete oestrogen
- **Oestrogen →** thickens urine lining **→** inhibits the secretion of FSH and LH → stimulates the secretion of LH → development of the female secondary sexual characteristic
- **LH : Luteinising Hormone -** bring on ovulation
- **Progesterone →** Maintain of uterus lining, Inhibits FSH, LH
- HCG - pregnancy hormone - maintains corpus letup
What causes the egg to mature
LH
Causes ovaries to secrete oestrogen
FSH - Follicle Stimulating Hormone
What thickens the lining
Oestrogen
What does a hormone graph look like with the four hormones
Follicular phase - all steady - progesterone and oestrogen starts to increase
Ovulation - 3 peak - LH on top with FSH at the bottom but progesterone steadies out
Luteal Phase - progesterone top and oestrogen bottom peace
Gymnosperm reproduction
pollination occurs by wind - starts as a haploid stage - seperate from female and male cones. small pollen grains from male cones transport to female.
Identify rhimzones and give an example
Ginger : underground stem to new shoots and roots - along the bottom of the growth and stems along the top.
Identify suckers and give an example
new shoots from roots ef wattle tree