nutrition in plants

Question 1

how do we know something is alive?

Answer 1

1. living things breathe
2. living things regenerate and reproduce
3. most living things move

Question 2

what are life processes?

Answer 2

various processes that take place in an organism like nutrition, respiration, etc. that are necessary for their survival are called life processes.

Question 3

what are some processes necessary for the survival of an organism?

Answer 3

1. nutrition
2. respiration
3. transportation
4. excretion

Question 4

define nutrition.

Answer 4

the process of intake of nutrients by an organism for its survival.

Question 5

types of nutrition.

Answer 5

1. autotrophic
   eg; plants
2. heterotrophic
   a) saprotrophic
   eg; mushroomsb) holozoic
   eg; humansc) parasitic
   eg; lice

Question 6

site of photosynthesis?

Answer 6

chlorophyll in the mesophyll layer of the leaf.

Question 7

features of a leaf that enable it to perform photosynthesis.

Answer 7

1. chloroplast to trap sunlight.
2. stomata for easy exchange of gasses.
3. broad surface area.
4. xylem and phloem to help in the transportation of minerals and nutrients respectively.

Question 8

draw diagram of the cross-section of a leaf.

Answer 8

check notebook.

Question 9

describe events during photosynthesis.

Answer 9

1. absorption of sunlight by chlorophyll.
2. conversion of light energy into chemical energy and splitting of water into hydrogen and oxygen.
3. reduction of carbon dioxide into carbohydrates.

Question 10

describe photosynthesis in desert plants.

Answer 10

desert plants take in carbon dioxide during the night. their stomata remain closed during the day to prevent loss of water through transpiration.

Question 11

structure of stomata.

Answer 11

1. tiny pores on the surface of a leaf.
2. lined by a pair of guard cells that have chloroplast and nucleus.
3. guard cells are lined by a special type of epidermal cells known as subsidiary cells.

Question 12

describe the opening and closing of stomata.

Answer 12

1. opening and closing of stomata are regulated by guard cells.
2. water from subsidiary cells moves into guard cells, making them turgid and opening stomata.
3. when water from guard cells moves into subsidiary cells they become flaccid and stomata close.