Biology Unit 1

What is photosynthesis?

Photosynthesis is the way that plants make their own food by using sunlight and nutrients like carbon dioxide from the air and water from the soil.

Where does photosynthesis take place?

inside the chloroplasts in a palisade cell

What is starch?

Starch is a carbohydrate made of thousands of glucose molecules linked together. They are insoluble in water and they are stored inside the chloroplasts in the plant cell

Word equation for photosynthesis

Carbon dioxide + water —-(light energy)—> Glucose + oxygen

What are variegated leaves?

Leaves with different colors

What are the 2 important mineral salts

nitrate and magnesium

What are the uses of nitrate

Nitrate is needed to make proteins that is needed to make new cells and to make chlorophyll

What is the use of magnesium

To make chlorophyll

Plants that are short of nitrate (and magnesium) are

stunted (small) and yellow

Plant cell with lots of water -

strong and firm

Plant cell with little water -

soft and floppy (if all the cells are like this, the plant is wilted")

What is xylem

Xylems are long tubes that transport water from the roots up to the leaves

How are leaves cooled

when water from xylem evaporates in the leaves, it absorbs heat energy and water vapour comes out of stoma

What are petals and their use

Petals are brightly colored to attract insects or birds to the flower, uses strong scents to attract insects and the insects or birds feed on nectar produced at the base of petals. Petals also have guidelines to direct insects to where they can find nectar

What is nectar

Nectar is a sugary substance that is produced at the base of petals

Pollen is produced in the —-

Anther

What contains the male gametes of the flower

Pollen grains

What contains the female gametes of the flower

Ovule

What are the male parts of a flower

Stamen(anther and filament), pollen containing male gametes

What are the female parts of a flower

Ovaries (ovule contaning female gametes) style, stigma

What are flowers

Flowers are organs that carry out sexual reproduction.

What is pollination

Pollination is the transfer of pollen from an anther to a stigma

What are the 3 types of pollination

insects, birds, wind

How do insects help in pollination

When insects come to the flower to collect nectar, the pollen gets stuck to their bodies and they fly to another flower where the pollen is rubbed off onto a stigma

How do birds help in pollination

same as in insects where the pollen gets stuck on to the wings and is rubbed off to onto a stigma

How does the wind help in pollination

Wind blows pollen off the anther and in luck, the pollen may land on the stigmas of other flowers

What is fertilisation

Fertilisation is the process of the nucleus of a male gamete and the nucleus of a female gamete joins together

What cell is formed after fertilisation and what does it do

Zygote, it divides and produce little groups of cells called an embryo.

After fertilisation, the ovule becomes the —

seed

After fertilisation, the ovary becomes the —

fruit

What is testa in bean seed

tough outer coat of the seed

What is micropyle in a bean seed

tiny hole where the pollen tube grew into the ovule

What are cotyledons

creamy-colored structures that cocntain food stores for the embryo (only reveals when testa is removed)

What is a fruit

A structure that contains seeds

What is seed dispersal

a process of spreading out seeds far away from the parent plant

Why is seed dispersal important

So that the seedlings dont need to compete for water, light and minerals from other seedlings or its own parent plant. It also allows the seedling to colonise new areas