Multicellular organisms

Question 1

how does a baby get oxygen and nutrients in the uterus?

Answer 1

the growing baby gets all the oxygen and nutrients it needs from the mother’s blood through the placenta and umbilical cord. The baby can also get rid of carbon dioxide and waste by going the opposite way. Bad things like alcohol and carbon dioxide can also be passed on to the baby this way.

Question 2

what is fertilisation?

Answer 2

fertilisation is when the nucleus of a sperm and egg join together. The new cell is called a zygote. This happens in the oviduct.

Question 3

In animals, what is the male and female sex cell and where is it produced?

Answer 3

Male: sperm produced in the testes
Female: egg produced in the ovaries

Question 4

why does sexual reproduction increase variety in offspring?

Answer 4

sexual reproduction increases variety in offspring because there is a mix of genes from mother and father

Question 5

how is a growing baby protected in the uterus?

Answer 5

the growing baby is protected in the uterus by an amniotic sac filled with amniotic fluid which acts as a cushion

Question 6

what happens to the zygote once it reaches the uterus?

Answer 6

it sinks into the lining of the uterus which is thick and cushioned with blood

Question 7

what is reproduction?

Answer 7

reproduction is the way to make new members of a species

Question 8

What is internal fertilisation?

Answer 8

Sperm needs something to swim in so it must be placed inside the female so there is liquid for them to move. This is called internal fertilisation because it happens inside the body

Question 9

What is external fertilisation?

Answer 9

Fish release their sperm and eggs into the water – this is called external fertilisation. This is less successful than internal because of other hungry fish that might eat the eggs

Question 10

What is the male sex cell in a flower?

Answer 10

The male sex cell is inside pollen produced by the anther

Question 11

What is the female sex cell in a flower?

Answer 11

The female sex cell is inside the ovule produced by the ovary

Question 12

What is pollination?

Answer 12

Pollination is the transfer of pollen from an anther to a stigma. Once pollen has landed on a stigma it grows a pollen tube down into the ovary so that fertilisation can take place

Question 13

What happens once the ovule has been fertilised?

Answer 13

Once the ovule has been fertilised it turns into a seed and the surrounding ovary develops into a fruit

Question 14

For the seed to form a new plant it has to be dispersed. What are the 3 ways to do this?

Answer 14

*wind (like in dandelions)
*animal internal (animals eat fruit)
*animal external (seed sticks to animal’s coat)

Question 15

What is asexual reproduction?

Answer 15

Asexual reproduction is when new plants are produced by a single parent

Question 16

does asexual reproduction increase or decrease variety?

Answer 16

The new plants formed by this method are genetically identical to the parent. This decreases variety

Question 17

What are some ways to asexually reproduce?

Answer 17

Ways to asexually reproduce include by tubers (potatoes), runners (Spider plant and strawberries) and bulbs (onions and daffodils)

Question 18

what are some of the differences between sexual and asexual reproduction?

Answer 18

Sexual reproduction involves two parents. All of the offspring produced are different from each other.
Asexual reproduction involves only one parent and all the offspring produced are identical to that parent.

Sexual reproduction is important for introducing variation in a population and enables species to adapt to changing environmental conditions.
Asexual reproduction does not produce variation but it allows populations to grow quickly.

Question 19

when are organisms members of the sane species?

Answer 19

Organisms are members of the same species if they can reproduce and make fertile offspring. E.g. horses and donkeys are not the same species because when they mate they produce mules which are infertile

Question 20

in what ways are humans different from each other?

Answer 20

Humans differ in many ways including gender, eye colour, hair colour and whether they can roll their tongue.

Question 21

what is variation controlled by?

Answer 21

Variation is controlled by genes. We receive two genes for every characteristic (one from our mother and one from our father)

Question 22

what is a dominant gene?

Answer 22

Dominant genes can overpower recessive genes. If someone has a dominant gene then it will be the only one that shows. Dominant genes get a capital letter for a symbol and recessive genes get the same letter but in lower case

Question 23

why do animals need food?

Answer 23

Animals need food for energy, protection and building material

Question 24

What are the 5 main food groups for humans?

Answer 24

Carbohydrates – Needed for energy (e.g bread)
Protein – Needed for growth & repair (e.g. meat)
Fat – Needed for energy (e.g. oil)
Minerals & Vitamins – Needed for protection from disease (e.g calcium, Vitamin C)

If you don’t have enough of these food groups in your diet you will get a deficiency. For example, someone with scurvy has no vitamin C.

Question 25

What effect can alcohol have on a growing baby in the uterus?

Answer 25

Alcohol can lead to slower growth and poor mental development

Question 26

What effect can lead have on a growing baby in the uterus?

Answer 26

Lead can affect development

Question 27

what is germination?

Answer 27

The growth of a seed into a plant is called germination. Germination needs warmth, oxygen and water.

Question 28

what does a plant need while is growing?

Answer 28

Once the plant is growing, it needs lots of light and carbon dioxide

Question 29

what is the function of the embryo root?

Answer 29

grows into the plants roots

Question 30

what is the function of the embryo shoot?

Answer 30

grows into the plants shoot

Question 31

what is the function of the food store

Answer 31

provides energy for growth

Question 32

what is the function of the seed coat

Answer 32

protects the seed

Question 33

what does propagating plants mean?

Answer 33

Propagating plants is making new plants by various methods
There are different methods to propagate plants, from seeds, cuttings, bulbs, tubers and runners

Question 34

what is planting seeds called?

Answer 34

planting seeds is called sowing

Question 35

what is a way to make plants grow better?

Answer 35

To make plants grow better, they can be grown in poly tunnels. This keeps them warm. The farmer might also want to hang lights

Question 36

what are cuttings?

Answer 36

Cuttings are small pieces of stem with some leaves attached, the new plant grows from this

Question 37

what are fertilisers used for?

Answer 37

Fertilisers can be used to help plants grow and to increase the yield (amount).
Fertilsers contain three key elements required by the plant; Nitrogen (for leaves), Phosphorous (for roots) and Potassium ( for fruit and flowers) (NPK). Rooting powder can also be used to improve the growth of roots.

Question 38

what can humans use plants for?

Answer 38

Humans can use plants as: food (e.g potatoes, wheat & rice), raw materials (e.g paper, furniture, fuel for burning) and medicines (e.g morphine from poppies).

Question 39

what is pharming?

Answer 39

pharming is when humans change crops to produce medicines. Medicines produced this way are easier and cheaper to produce than is currently possible.

Question 40

what are some examples of medically important products that are produced in plants?

Answer 40

Medically important products that could be produced in plants include antibodies, vaccines and hormones

Question 41

what is homeostasis?

Answer 41

Keeping the bodies internal environment (e.g. temperature or blood sugar) within ideal limits is called homeostasis.

Question 42

what are some changes in the body when it drops in temperature?

Answer 42

shivering, body hairs standing on end and the blood vessels get narrower and blood is diverted away from the skin.

Question 43

what are some changes in the body when it increases in temperature?

Answer 43

increased sweating and the blood vessels get wider and blood is diverted to the skin. Heat is lost through evaporation of sweat from skin and radiation.

Question 44

Control of blood glucose levels (sugar) is carried out the hormones released by the…

Answer 44

pancreas

Question 45

what hormones does the pancreas produce?

Answer 45

insulin and glucagon which are involved in the storage and release of glucose in the liver. They both travel round the body in the blood

Question 46

What happens if glucose levels are too high in the body?

Answer 46

If blood glucose levels are too high, insulin is released. This tells the body to store the excess glucose in the liver. This brings the blood glucose levels back to normal

Question 47

what happens if blood levels are too low in the body?

Answer 47

If blood levels are too low this excess glucose can be released again through the action of Glucagon bringing them back to normal

Question 48

what is diabetes?

Answer 48

Diabetes is a condition where patients don’t produce enough insulin to control their blood glucose and can be fatal. It is caused by either a failure of the pancreas to release insulin (Type 1) or failure of the liver to respond to insulin (Type 2)

Question 49

How often do people with type 1 diabetes have to test their blood glucose and how often do they need to inject insulin?

Answer 49

People with Type 1 diabetes need to test their blood glucose concentration regularly and inject insulin with every meal. This insulin is made by genetic engineering