B11-Hormonal Coordination Flashcards

Question

Compare effectiveness of 3 types of contraception;

Answer 1

hormone‑based: relatively effective (0–10% failure rate per Figure 2), open to human error barrier: less effective (12–18% failure rate per Figure 2), open to human error or damage surgical: very effective, not open to human error following successful surgery

Answer 2

The oral contraceptive, which is known as the pill, contains oestrogen or progesterone . These hormones inhibit the production of FSH , and eggs cannot mature

Answer 3

IVF involves giving a mother FSH and LH to stimulate the maturation of several eggs. The eggs are collected from the mother and fertilised by sperm from the father in a dish in the laboratory. The fertilised eggs develop into embryos. At the stage when they are tiny balls of cells one or two embryos are inserted into the mother's uterus (womb)

Answer 4

Some women have difficulty becoming pregnant because they don't produce enough FSH to allow their eggs to mature. Fertility drugs contain FSH and LH, which stimulate eggs to mature in the ovary.

Answer 5

Advantages of IVF It allows people to have babies of their own, who otherwise can't due to a variety of reasons. It has a safe track record and has been used since 1978. The embryos can be screened for genetic diseases, which is important for families that already have an affected child. Only unaffected embryos are used. Unused eggs can be used for research or donated to other couples. Disadvantages of IVF There are side effects form the drugs used, such as hot flushes and severe headaches. There is a possibility of multiple births, which is dangerous for mother and babies. Ovarian hyper-stimulation syndrome (OHS), when too many eggs develop in the ovaries. It is very emotionally and physically stressful. The success rates are not high.

Answer 6

positive tropisms – the plant grows towards the stimulus negative tropisms – the plant grows away from the stimulus

Answer 7

Phototropism is a response to the stimulus of light. Geotropism/Gravitropism is a response to the stimulus of gravity

Answer 8

Plant hormones that control cell elongation.

Answer 9

They are mostly made in the tips of the growing stems and roots, which are known as apical meristems, and can diffuse to other parts of the stems or roots. Auxins control the growth of plants by promoting cell division and causing elongation in plant cells (the cells get longer). Stems and roots respond differently to high concentrations of auxins: cells in stems grow more cells in roots grow less

Answer 10

In a stem, the shaded side contains more auxin and grows longer, which causes the stem to grow towards the light. Auxins have the opposite effect on root cells. In a root, the shaded side contains more auxin and grows less - causing the root to bend away from the light.

Answer 11

Investigate the effect of light or gravity on the growth of newly germinated seedlings Record the results of the seeds' length measurements and create a labelled biological drawing to illustrate the effects of light or gravity. Germination is the beginning of plant growth, and the plant will continue to grow if the correct conditions are available. Mustard or cress seeds are a good choice for this investigation because they grow fast and their roots and stems are clearly visible. Variables The independent variables for this investigation are to place plants in light and dark conditions. Other suitable independent variables are: different colours of light, intensity of light or the direction light comes from. The dependent variable is the mean height of seedlings. Control variables are the number of seeds on each dish, how much they are spread out, the volume of water the seedlings are given, the temperature they are kept at. Method Put cotton wool into three petri dishes, and add the same volume of water to each dish. Add ten seeds to each dish and place them in a warm place where they won’t be disturbed. Allow the seeds to germinate, and add more water if the cotton wool dries out. Once the seeds have germinated, ensure the petri dishes each contain the same number of seeds, and remove any extra seeds if necessary. One petri dish will sit in full light on a windowsill, the second will be in a dark cupboard, and the final dish will be placed in partial light. Every day for one week, measure the height of each seedling and record the results in a table. You must record the height of the individual seedlings on each day. Calculate the mean of the seedlings each day, and compare the mean heights in the three different locations.

Answer 12

end seed dormancy promote flowering increase fruit size

Answer 13

Ethene is a hydrocarbon gas which speeds up ripening in fruit. It also controls cell division during plant growth. In the food industry fruit is often picked unripe and then transported. This prevents fruit from over-ripening on the journey. It is ripened during storage by adding ethene and then taken to the shops.

Answer 14

as weed killers as rooting powders for promoting growth in tissue culture

Answer 15

Weedkillers A dandelion. Selective weedkillers kill some plants, but not others. This can be useful for getting rid of dandelions in a lawn without killing the grass or weeds that compete with crops such as wheat. The selective weedkiller contains a growth hormone that causes the weeds to grow too quickly and die. Because most weeds have broader leaves than grass or wheat, the weedkiller is absorbed in larger quantities by the weeds. A plant cutting being dipped into rooting powder. Selective weedkillers kill plants that some species of animals rely on as a food source. This can result in a reduction of biodiversity.

Answer 16

Plant cuttings can be dipped in hormone rooting powder before planting. Synthetic plant hormones are used to control plant growth. For example, rooting powder contains growth hormones that make stem cuttings develop roots quickly.

B11-Hormonal Coordination Flashcards

i hate my life and when i dragged into hell im taking this chapter down with it (40 cards)