B1

Question 1

what are the differences between prokaryotic and eukaryotic cells?

Answer 1

prokaryotic much smaller than eukaryotic cells
eukaryotic cells contain membrane-bound organelles contain genetic information in the nucleus

Question 2

what is the prokaryotic cell wall composed of

Answer 2

Peptidoglycan

Question 3

how is genetic information stored in a prokaryotic cell

Answer 3

in plasmids- small circular loops of DNA found in the cytoplasm
- which carry genetic advantages such as antibiotic resistance.
Chromosomal DNA- singular large loop of circular DNA

Question 4

explain how xylem plants are adapted to their function

Answer 4

-no upper or lower margins between the cells , to provide continuous route for water flow

• original cell wall between cells has broken down - hollow structure
• xylem walls are strengthened with lignin , to prevent breakages

-thick woody side walls strengthen their structure and prevent collapse.

-cells are dead with out organelles or cytoplasm to allow free passage of water

Question 5

what is xylem vessels specific function

Answer 5

-xylem vessel is apart of the vascular tissue in plants and its responsible for transporting water and dissolved minerals from roots to the leaves
- water can be used in photosynthesis
-minerals can used to build other molecules such as proteins and chlorophyll

Question 6

what is phloem vessels function

Answer 6

phloem is apart of the vascular tissue in plants and is responsible for transporting sucrose and amino acids

• phloem’s transports direction can vary depending on the source of the nutrients and where they’re needed

Question 7

how are phloem vessels adapted to their function

Answer 7

• phloem cells form similarly tubes like xylem vessels but retain sub-cellular structures and therefore are living
• they are joined end to end and contain holes in the end cell walls - this are called sieve plates , forming tubes which allows sugars and amino acids to flow through by translocation
• sieve plates which let dissolved amino acids and sugars be transported up and down the stem
• sieve plates kept alive by companion cells, which provide energy for active transport of a substance along the phloem does with mitochondria for energy transfer.

-cells have few sub-cellular structures to aid the flow of materials

Question 8

define translocation

Answer 8

Translocation is the process by which materials in the plant are moved from where they are made to where they are needed.si