Increase in quantity but unchanged form

Cells continuously absorb nutrients from the surrounding environment and convert them into their own substances. The size of cells increases from small to large, and when they grow to a certain size, they divide.

The larger the cell, the slower it absorbs external substances.

Nuclear division→Plasmonic division→Formation of new membrane→Inward depression of the middle part of the cell (constriction)

Plant cells also form new walls

Cell division process from the inside out

DNA

protein

DNA is the genetic material, and chromosomes are the carriers of genetic material.

Copy first, then divide equally

The new cells contain the same genetic material as the original cells

Formation: Cells divide to produce offspring, which undergo differential changes in morphological structure and physiological functions.

Concept: Cells with the same structure and function are united to form

Differentiation into morphological changes, reflecting the characteristics of structure and function adaptation

epithelial tissue

muscle tissue

nervous tissue

connective tissue

Spindle disappears

A structure composed of different organizations put together in a certain order to perform certain functions

Multiple organs that can jointly complete several physiological functions are combined in a certain order

digestive system

respiratory system

exercise system

circulatory system

urinary system

nervous system

Endocrine System

reproductive system

root

stem

leaf

flower

fruit

seed

Protect

skin surface

support and protect

cell wall thickness

stems, leaves

catheter

Sieve tubes (bark)

Tubular

Store nutrients, photosynthesis

Cell wall is thin, contains chloroplasts, and has large vacuoles

flowers, fruits, roots

Cells are more active

Large nucleus

Stem tip, root tip, etc.

Digestion

feeding

sports

big core

small core

breathe

excretion

red tide

Algae blooms (discharge into fresh water)